Heartburn, chest pain and digestive distress are symptoms that we commonly associate with GERD. But there are certain symptoms that we wouldn’t normally think might be caused by acid reflux and that is what makes the condition more damaging. This is because you try to treat the symptom not realizing that it might actually be due to acid reflux and fail to make the connection. One such symptom of GERD is chronic cough.
Ryan D Madanik, M.D. at the University of North Carolina School of Medicine, Division of Gastroenterology & Hepatology, Center for Esophageal Diseases and Swallowing estimates that GERD may be responsible for as high as 25% (that is 1 in every 4!) of cases of chronic cough. The worst part is that the majority of patients who have cough do not exhibit any classical symptoms of GERD such as heartburn. This makes it even more difficult to diagnose GERD as the actual reason for cough.
There are certain clues to suggest that a persistent cough may be actually due to GERD. A GERD-related cough usually occurs during the night or after a meal (when acid reflux often is at its worst). Coughing can also occur when you are lying down. If you do not find any X-ray reports to suggest that the reason might be something else or the cough happens without post-nasal drip or asthma, it could be related to GERD. GERD-related cough is present even without the presence of common causes like smoking or taking certain medications that might make a cough worse.
There are a couple of theories that have tried to explain why GERD causes cough. The most common explanation is that when acidic contents of the stomach reflux into the esophagus, they sometimes travel above the upper esophageal sphincter. The upper esophageal sphincter is a muscular valve that guards the openings of the pharynx (airway) and the esophagus (food pipe). When you breathe in air, the sphincter is closed so as to allow the air to enter the airway and into the lungs, and not the stomach. When you swallow saliva or food, it opens to allow it to enter the stomach. The acidic reflux forms very small droplets, called microdroplets, that enter the larynx (voice box) or the bronchial tree (the network of airways inside the lungs). Now, it is a common human physiologic mechanism to remove any irritant that has either entered the larynx or the bronchial tree. In this case, this mechanism is cough.
Another, a bit more complex, mechanism is as follows. While a cough may often seem like an irritant, each cough is a complex sensory mechanism (called the reflex arc) that involves nerves and muscles. Studies have found that a part of this sensory reflex arc is present in the lower respiratory tract. This arc is called the esophageal-bronchial reflex. Scientists believe that this arc evolved as a defense mechanism against reflux rising upwards and entering the lungs. So, when the refluxate (acidic contents of the stomach) rises above the upper esophageal sphincter, a person may start coughing because the arc has been stimulated.
Constant coughing can lead to further inflammation and soreness of the throat and larynx, leading to hoarseness and difficulty in swallowing.
Coughing can also put pressure on the diaphragm muscles and every cough pulls them upwards. The diaphragm is a muscular wall that separates the thoracic cavity (that houses upper organs like the heart, the lungs) and the abdominal cavity (that houses organs like stomach, liver, intestines, etc.). The esophagus enters the stomach through a small hole in the diaphragm called the hiatus. Constant pulling of the diaphragm can lead to hernia, a condition in which the upper part of the stomach is pulled through the hiatal opening to rest inside the thoracic cavity, a place it has no business being. This condition, called hiatal hernia, can worsen GERD as it weakens the lower esophageal sphincter, leading to a backflow of acidic contents from the stomach into the esophagus.
GERD-related cough is slightly more complicated than one would imagine because it can be caused by both acidic as well as non-acidic stomach contents. Highly acidic contents of the stomach may cause heartburn due to the burning and inflammation of the sensitive esophageal lining that is clearly not meant to resist stomach acidity. Non-acidic stomach contents include bile and pepsin (an enzyme that breaks down parts of protein).
Patients with GERD-related cough fall into two groups. A smaller group consists of patients who show the primary symptoms of GERD, such as heartburn, and a secondary problem such as cough. The second, larger group consists of patients who do not show the classical symptoms of GERD and only present with a chronic cough. The second group does not respond well to conventional GERD therapy (acid-blocking therapy).
Another major problem is in the diagnosis of the second group. Because this group does not show any classical GERD symptoms and only present with cough, it is very difficult to say that the cough might actually be due to GERD. It is usually a time-consuming trial-and-error method to first treat a cough through regular treatments. If it does not respond to conventional medication, the next method is to perform certain tests that might point to GERD being the reason for the cough.
And thus, currently, there is no conventional treatment regimen for GERD-related chronic cough. We have talked a lot on our site about treating GERD through a holistic Functional Medicine approach. We have looked at the real causes of GERD and how the root cause of this condition can be treated.
Chronic coughing is a serious symptom of GERD and is very difficult to diagnose. Physicians are trained to consider GERD as the potential cause of chronic cough when other reasons cannot explain its presence. However, conventional medicine has no answer to this condition. This problem needs a holistic Functional Medicine approach whereby if a cough is present and no treatment is found effective, the underlying problem should be regarded as GERD. And the root cause of the problem should be treated. A Functional Medicine approach endeavors to correct the imbalance of the bodily functions that has caused a chronic condition.
Management of GERD-Related Chronic Cough
The cough reflex and its relation to gastroesophageal reflux